Instructions:
Preheat the oven to 350°F. Combine 1 cup of the sugar and the water in a small, heavy saucepan and cook over low-medium heat until the sugar dissolves and turns a dark golden color (once it starts changing color, swirl it around so it caramelizes evenly). Divide among 6 smaller ramekins (or one larger 8-inch ramekin) and swirl around to coat the bottoms. Combine the half-and-half and canela (if using vanilla, split lengthwise with the tip of a knife and add the seeds and the pod) in a saucepan and bring to a simmer over medium heat. Remove from the heat and cover. Allow to steep for 15 minutes to extract the flavor. Meanwhile, mix together the egg yolks and canna butter, the remaining 3/4 cup sugar, the vanilla, and the salt in a large heat proof mixing bowl placed on a towel to keep it from wobbling while whisking in the hot liquid. Slowly ladle about 1 cup of the hot infused milk into the egg mixture while whisking. Add the egg mixture back to the milk while you whisk gently (try to prevent excess air bubbles from forming). Strain and use right away or chill it over an ice bath to us e another day (it can be made up to 3 days ahead). Place the prepared ramekins evenly spaced in a towel-lined baking dish to keep them from sliding. Divide the mixture among the ramekins and pop any bubbles with a spoon. Carefully pour hot water to fill three-fourths of the way up sides of the baking dish and cover loosely with aluminum foil (you can also make a few holes in the foil to prevent steaming). Bake until the flans are set around the edges but slightly jiggly in the center, about 30 minutes. Remove the baking dish from the oven and remove the ramekins with a towel or tongs. Let cool, uncovered, until they feel cool to the touch and then chill in the refrigerator for at least 6 hours (this can be done a day in advance). To unmold, fill a bowl or small pot with 2 to 3 inches of very hot water. Dip a small, sharp knife in the hot water, dry it quickly, and run it around the edges of the ramekins. Dip the bottoms of the ramekins into the hot water for about 20 seconds and unmold onto a plate. The flan should slowly unmold but if it feels a bit stuck, run a knife around the edges once again. Serve chilled or at room temperature.